|Publication Type:||Journal Article|
|Year of Publication:||2006|
|Authors:||Hipp, A. L., Reznicek, A. A., Rothrock, P. E., Weber J. A.|
|Journal:||International Journal of Plant Sciences|
|Keywords:||ancestral character state reconstruction, Carex section Ovales, Carex section Stellulatae, Carex subgenus Vignea, DNA, evolution, hybrid speciation, incongruence, intergenic spacer, length difference test, model, north-america, nuclear, ribosomal DNA, sedges carex, SEQUENCE DATA, vignea cyperaceae|
Section Ovales is the most species-rich section of the sedge genus Carex in the New World. Phylogenetic analyses of molecular data recover a predominantly New World clade as sister to a solitary east Asian species, C. maackii. Nuclear ribosomal DNA are congruent in the placement of all taxa within the section, with a solitary exception: incongruence between ITS and ETS data in the placement of C. bonplandii and C. roraimensis suggests a hybrid origin for this lineage. Biogeography correlates strongly with phylogeny in the section, but there have been at least two instances of long-range dispersal, one from an eastern North American clade to western North America and one from the New World to Eurasia. Morphological characters studied are all homoplastic. Developing a comprehensive infrasectional classification with a phylogenetic basis would be complicated by the fact that most of the novel morphological characters in the section have evolved within relatively small, independent clades.